Laser Harp

If you would like to buy a Laser Harp or Laser Harp plans, contact me at egoodchild@goodchildengineering.com and check out the Laser Harp Gen 2

The Laser Harp is a musical instrument that uses laser beams as the interactive media that the user interfaces with to create the music. The laser harp is a digital instrument meaning that it doesn't create any sound by it's self. Rather it sends a digital signal using the MIDI protocol to a computer or synthesizer where it is then converted into actual audio. This type of laser harp is know as "Frameless" in that there is no sensor at the end of each beam, rather it uses the principle of light reflected back form the player's hand as a trigger. Although this method is vastly more complex than the framed design it much more versatile in that you can have as many beams as needed and also a much more compact design.

Generation 1 Laser Harp Code name "Python"




Hardware/Software Specs
  • Arduino 16Mhz CPU
  • 20Kpps Galvo
  • 8-Bit 500Kb/s DAC
  • 450mW Green DPSS 
  • Light to voltage converter Sensor + Opamp Beam Sensor 
  • C++ ~1500 lines of code
During development I tried many different DAC solutions. My first harp used an 8-bit digital SPI potentiometer. Although this worked fine for 10 beams it lacked the resolution and speed needed for a 12 or 13 beam harp. So I made the decision to move to a 12-bit split rail DAC with 2Mb/s Throughput made by Texas Instruments.  This seems to be working well and is part of the development for the Generation 2 Harp. 

The senor used was  a very simple light to voltage converter with internal gain. An external opamp and comparator where also added to squared off the output in prep for the MCU's interrupt input.   

The microcontroller used in the gen 1 harp was anAarduino atmega328p running at 16MHz. This MCU provided all the processing needed to both drive the DAC and read the data from the sensor.   

   
     



















Generation 2 Laser Harp Code name "Cobra"  

The generation 2.0 laser harp is currently under development. The gen 2 will also be available for general sale to the public. Some of the features included in the Gen 2 harp will be:

  • ATZMEGA 32MHZ CPU
  • 500+mW Green DPSS
  • 40Kpps Galvos 
  • 13 beams 
  • Programmable beams to note assignments
  • Pedal Controls for open/close action and octave change
  • New advanced interference proof beam sensor.  

Here are some development photos

             
        


























More to come on Laser harp development. If you are interested in buying a Gen2 when they come out feel free to contact me for more information at egoodchild@goodchildengineering.com